IOWA ST: The Cyclones poor offense (364 YPG, 96th in FBS) lost QB Steele Jantz and its top three receivers. QB Sam Richardson (8 TD, 1 INT) will start in this run-heavy offense that returns four O-Line starters and its top two rushers in RBs James White (505 rush yds) and Shontrelle Johnson (504 rush yds). The 98th-ranked defense (442 YPG allowed) lost a ton, but LB Jeremiah George (87 tackles) and S Jacques Washington (90 tackles, 3 INT) both return.

(AP) - Just as it was throughout the preseason, the identity of No. 19 Oklahoma State's starting quarterback remains a mystery.

Sophomore J.W. Walsh seized the starting role for the Cowboys (5-1, 2-1 Big 12) in the season-opening victory over Mississippi State, and after showing flashes of brilliance in subsequent games, appeared to solidify his role.

But after a shaky start in last Saturday's 24-10 win over TCU, Walsh was replaced in the second quarter by senior Clint Chelf, who was solid but not spectacular in relief.

Now, not even the coaching staff is sure who will be starting when the Cowboys visit Iowa State (1-5, 0-3) on Saturday.

"We're going to work both players the way we have, they get equal reps each week and see how it goes," said coach Mike Gundy, who plans on revealing the starter at game-time. "We've just started looking at Iowa State, we'll come up with a game plan and try to work it in to our quarterback that we think gives us the best chance to win."

After completing 9 of 18 passes for 115 yards but also throwing two interceptions, Walsh came out early in the second quarter with OSU leading TCU 7-0.

"Just kind of a gut feeling, not really anything different than I felt like we kind of needed a change at that time," Gundy said.

Chelf, who last played significant minutes in second-half mop-up duty in the Cowboys' 59-3 win over Lamar on Sept. 14, threw an interception on his first play from scrimmage. After that, though, he settled down, completing 10 of 25 passes for 178 yards.

"I think at times, both quarterbacks played well, I think at times, both quarterbacks had some mistakes out there," offensive coordinator Mike Yurcich said. "I think we left a lot of points out there on the field. Neither quarterback played extremely well. Both made mistakes and both made some plays."

As far as the Oklahoma State receivers are concerned, it doesn't really matter who lines up under center.

"There's no change on my part," said senior Tracy Moore, who had five receptions for 77 yards against TCU. "They both can throw, but from a receiver's standpoint, you got to know the play-calling is going to be a little different, to play to (the starter's) strengths and not the other quarterback's strengths. That's one thing you've got to be mindful of."

Plus, it's not like Cowboy receivers haven't had to adjust to playing with different quarterbacks before. Last season, more due to injuries than performance issues, Walsh, Chelf and Wes Lunt all played.

"We went through three quarterbacks last year and we all did it well," said Stewart, a senior who pulled in a game-high 10 receptions for 141 yards last Saturday. "So I don't want to say it's hard, but it's different. None of them throw the same, but then again, they both get the ball to you, so that's all that matters. Whoever we go with as our quarterback, we're good with them as our leader to take the field, we're confident with either one of them. As long as we're scoring points, that's all that matters."

No matter who takes the field with the starters in Ames, Iowa, there's no guarantee that will be the same QB who finishes the game.

"I think you just have to see how it goes," Gundy said of whether he would consider rotating quarterbacks. "I don't think we can really predict how things will transpire from this point forward, and we're very open and honest with both of them, and I think that benefits our team. It's never a perfect situation. We're just going to move forward and we're fortunate they're both good, quality kids."

Walsh may get a longer look after having a career day in a 31-10 home win over Iowa State last season. He completed 32 of 47 passes for 415 yards and a touchdown, and ran nine times for 46 yards and another score.

This will be the Cyclones' third straight game against a Top 25 team following a 42-35 loss at then-No. 20 Texas Tech on Oct. 12 and a 71-7 defeat at then-No. 12 Baylor last Saturday.

Iowa State also replaced its starting quarterback when Sam Richardson went to the sidelines and redshirt freshman Grant Rohach took over while Baylor pulled away in the second quarter. Richardson came back in the second half, but it didn't matter much.

Richardson and Rohach combined for just 133 yards passing with an interception apiece and five sacks between them. Richardson went down three times, and Baylor had 10 tackles for loss, causing the Cyclones to finish with 41 yards rushing because they had 47 yards in losses. They managed 174 yards of total offense, 57 coming on a late scoring drive.

"There's a lot that wasn't done. It's not just that quarterback position," coach Paul Rhoads said.